4,753 research outputs found
Ultra wideband: applications, technology and future perspectives
Ultra Wide Band (UWB) wireless communications offers a radically different approach to wireless communication compared to conventional narrow band systems. Global interest in the technology is huge. This paper reports on the state of the art of UWB wireless technology and highlights key application areas, technological challenges, higher layer protocol issues, spectrum operating zones and future drivers. The majority of the discussion focuses on the state of the art of UWB technology as it is today and in the near future
Initial synchronisation of wideband and UWB direct sequence systems: single- and multiple-antenna aided solutions
This survey guides the reader through the open literature on the principle of initial synchronisation in single-antenna-assisted single- and multi-carrier Code Division Multiple Access (CDMA) as well as Direct Sequence-Ultra WideBand (DS-UWB) systems, with special emphasis on the DownLink (DL). There is a paucity of up-to-date surveys and review articles on initial synchronization solutions for MIMO-aided and cooperative systems - even though there is a plethora of papers on both MIMOs and on cooperative systems, which assume perfect synchronization. Hence this paper aims to ?ll the related gap in the literature
Cross-layer Resource Allocation Scheme for Multi-band High Rate UWB Systems
In this paper, we investigate the use of a cross-layer allocation mechanism
for the high-rate ultra-wideband (UWB) systems. The aim of this paper is
twofold. First, through the cross-layer approach that provides a new service
differentiation approach to the fully distributed UWB systems, we support
traffic with quality of service (QoS) guarantee in a multi-user context.
Second, we exploit the effective SINR method that represents the
characteristics of multiple sub-carrier SINRs in the multi-band WiMedia
solution proposed for UWB systems, in order to provide the channel state
information needed for the multi-user sub-band allocation. This new approach
improves the system performance and optimizes the spectrum utilization with a
low cost data exchange between the different users while guaranteeing the
required QoS. In addition, this new approach solves the problem of the
cohabitation of more than three users in the same WiMedia channel
Performance of MB-OFDM UWB and WiMAX IEEE 802.16e converged radio-over-fiber in PON
Experimental results about the performance of converged radio-over- fiber transmission including multiband- OFDM UWB and WiMAX 802.16e wireless over a passive optical network are reported in this paper. The experimental study indicates that UWB and WiMAX converged transmission is feasible over the proposed distribution set-up employing a single wavelength. However, the results indicate that there is an EVM penalty of 3.2 dB for a UWB 10 km SSMF transmission in presence of WiMAX wireless
Joint distribution of polarization-multiplexed UWB and WiMAX radio in PON
In this paper, the feasibility of the joint distribution of ultra-wideband (UWB) and WIMAX wireless using polarization multiplexing as a coexistence technique is proposed and experimentally demonstrated within the framework of passive optical networks (PON). Four single- and orthogonal-polarization multiplexing schemes are studied targeting to reduce the mutual interference when UWB and WiMAX are distributed jointly through standard single-mode fiber (SSMF) without transmission impairments compensation techniques and amplification. Experimental results indicate successful transmission up to 25 km, in SSMF exceeding the range in typical PON deployments. The radio link penalty introduced by optical transmission is also investigated in this paper
Ultra-wideband radio signals distribution in FTTH networks
The use of an ultra-wideband (UWB) radio technique is proposed as a viable solution for the distribution of high-definition audio/video content in fiber-to-the-home (FTTH) networks. The approach suitability is demonstrated by the transmission of standards-based UWB signals at 1.25 Gb/s along different FTTH fiber links with 25 km up to 60 km of standard single-mode fiber length in a laboratory experiment. Experimental results suggest that orthogonal frequency-division-multiplexed UWB signals exhibit better transmission performance in FFTH networks than impulse radio UWB signals
Novel wireless modulation technique based on noise
In this paper, a new RF modulation technique is presented. Instead of using sinusoidal carriers as information bearer, pure noise is applied. This allows very simple radio architectures to be used. Spread-spectrum based technology is applied to modulate the noise bearer. Since the transmission bandwidth of the noise bearer can be made very wide, up to ultra-wideband regions, extremely large processing gains can be obtained. This will provide robustness in interference-prone environments. To avoid the local regeneration of the noise reference at the receiver, the Transmit-Reference (TR) concept is applied. In this concept, both the reference noise signal and the modulated noise signal are transmitted, together forming\ud
the bearer. The reference and modulated signals are separated by applying a time offset. By applying different delay times for different channels (users) a new multiple access scheme results based on delay: Delay Division Multiple Access (DDMA). A theoretical analysis is given for the link performance of a single-user and a multi-user system. A testbed has been built to demonstrate the concept. The demonstrator operates in a 50 MHz bandwidth centered at 2.4 GHz. Processing gains ranging from 10Âż30 dB have been tested. The testbed confirms the basic behavior as predicted by the theory
Laboratory Experiments on 5G Cellular Technologies - A Case Study on the Synergy of Research and Experiential Learning
Teaching and research complement each other. This is
an advice often given to young professors, to encourage
them to find synergy between research and teaching, i.e., to
let research aid teaching, and vice-versa. When a professor
develops new laboratory experiments for undergraduate
courses in wireless communications, he/she may find it
difficult to replicate research experiments, because they
require expensive equipment, usually available in
âresearch, non-teachingâ laboratories. In this paper, we
present a wireless laboratory that is used for both research
and teaching. We show how the research on fifth
generation (5G) cellular networks - including millimeter
wave transmission, ultra-wideband wireless
communications, and multiple-input-single-output (MISO)
antennas â helped develop laboratory experiments for
undergraduate engineering students. The experiments not
only teach students about 5G technologies, but also how to
use real-time spectrum analyzers, vector signal generators,
arbitrary waveform generators, and signal analyzers, which
will help their engineering and/or research careers.Cockrell School of Engineerin
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